Triple clutch multi-speed transmission

Abstract

A transmission is disclosed having a planetary gear set with three input torque-transmitting mechanisms, such as friction clutches, to achieve torque flow through the planetary gear set to a countershaft gearing arrangement. The transmission includes an input member, an output member, a planetary gear set, an input clutch assembly having three input clutches and a countershaft gearing arrangement. The countershaft gearing arrangement is operatively connected with the planetary gear set and includes: at least three co-planar intermeshing gears, first and second countershafts, a first intermediate shaft and a second intermediate shaft concentric with the first intermediate shaft.

The invention claimed is: 
     
       1. A transmission comprising:
 an input member; 
 an output member; 
 a planetary gear set having first, second and third members; 
 a clutch assembly having a first, a second and a third torque-transmitting mechanism each selectively engageable to connect the input member with a respective different one of the members of the planetary gear set; 
 a first intermediate shaft connected for common rotation with the first member of the planetary gear set, wherein the first intermediate shaft is concentric with the input shaft; 
 a second intermediate shaft connected for common rotation with the second member of the planetary gear set, wherein the second intermediate shaft is concentric with the first intermediate shaft; 
 a first countershaft radially offset from the intermediate shafts; 
 a second countershaft radially offset from the intermediate shafts; 
 a first countershaft transfer gear connected for common rotation with the first countershaft and in communication with the output member to transfer torque from the first countershaft to the output member; 
 a second countershaft transfer gear connected for common rotation with the second countershaft and in communication with the output member to transfer torque from the second countershaft to the output member; 
 at least three co-planar intermeshing gear sets, wherein at least one of the gears of the at least three co-planar intermeshing gear sets is fixed for common rotation with at least one of the intermediate shafts and one of the at least three co-planar intermeshing gears includes a first gear in mesh with a second and third gear; and 
 a plurality of synchronizers, wherein at least one of the plurality of synchronizers is selectively engagable to connect at least one of the gears of the at least three co-planar intermeshing gear sets with at least one of the first and second countershafts for common rotation therewith and wherein at least one other of the plurality of synchronizers is selectively engageable to connect at least one of the gears of the at least three co-planar intermeshing gear sets with at least one other of the gears of the at least three co-planar intermeshing gear sets, thereby transferring torque from the planetary gear set to at least one of the first and second countershaft transfer gears through at least one of the intermediate shafts and at least one of the sets of co-planar intermeshing gear sets. 
 
     
     
       2. The transmission of  claim 1  wherein the first member of the planetary gear set is a sun gear, the second member of the planetary gear set is a planet carrier member and third member of the planetary gear set is a ring gear. 
     
     
       3. The transmission of  claim 2  wherein the planet carrier member rotatably supports a first and second set of planet gears and wherein the first set of planet gears intermeshes with the sun gear and the second set of planet gears and the second set of planet gears intermeshes with the ring gear and the first set of planet gears. 
     
     
       4. The transmission of  claim 2  wherein the first intermediate shaft is connected for common rotation with sun gear of the planetary gear set. 
     
     
       5. The transmission of  claim 2  wherein the second intermediate shaft is connected for common rotation with the planet carrier member of said planetary gear set. 
     
     
       6. The transmission of  claim 2  wherein the first torque-transmitting mechanism is selectively engageable to connect the input member with the ring gear of the planetary gear set, the second torque-transmitting mechanism is selectively engageable to connect the input member with the planet carrier of the planetary gear set and the third torque-transmitting mechanism is selectively engageable to connect the input member with the sun gear of the planetary gear set. 
     
     
       7. The transmission of  claim 1  wherein two of the at least three co-planar intermeshing gears includes a first gear in mesh with a second gear. 
     
     
       8. The transmission of  claim 7  wherein the first gear of each of the at least three co-planar intermeshing gear sets is fixedly connected to the first intermediate shaft. 
     
     
       9. The transmission of  claim 7  wherein the second gears of two of the at least three co-planar intermeshing gear sets are selectively engageable with the first countershaft and the second gear of the remaining one of the at least three co-planar intermeshing gear sets and the third gear of the two of the at least three co-planar intermeshing gear sets are selectively engageable with the second countershaft. 
     
     
       10. The transmission of  claim 1  wherein the plurality of synchronizers further includes a first synchronizer for selectively connecting a second gear of a first of the at least three co-planar intermeshing gear sets with a second gear of a second of the at least three co-planar intermeshing gear sets. 
     
     
       11. The transmission of  claim 10  wherein the plurality of synchronizers further includes a second synchronizer for selectively connecting a third gear of the first of the at least three co-planar intermeshing gear sets with the second countershaft. 
     
     
       12. The transmission of  claim 11  wherein the plurality of synchronizers further includes a third synchronizer for selectively connecting a second gear of a second of the at least three co-planar intermeshing gear sets with the first countershaft. 
     
     
       13. The transmission of  claim 12  wherein the plurality of synchronizers further includes a fourth synchronizer for selectively connecting a second gear of the third of the at least three co-planar intermeshing gear sets with the second countershaft. 
     
     
       14. The transmission of  claim 1  wherein the output member further includes an output transfer gear in mesh with each of the first and second countershaft transfer gears. 
     
     
       15. A transmission comprising:
 an input member; 
 an output member; 
 a planetary gear set having a sun gear, a carrier member and a ring gear, wherein the carrier member rotatably supports a first and second set of planet gears and wherein the first set of planet gears intermeshes with the sun gear and the second set of planet gears and the second set of planet gears intermeshes with the ring gear and the first set of planet gears; 
 a clutch assembly having a first, a second and a third clutch, wherein the first clutch is selectively engageable to connect the input member with the ring gear of the planetary gear set, the second clutch is selectively engageable to connect the input member with the carrier member of the planetary gear set and the third clutch is selectively engageable to connect the input member with the sun gear of the planetary gear set; 
 a first intermediate shaft connected for common rotation with the sun gear of the planetary gear set, wherein the first intermediate shaft is concentric with the input shaft; 
 a second intermediate shaft connected for common rotation with the carrier member of the planetary gear set, wherein the second intermediate shaft is concentric with the first intermediate shaft; 
 a first countershaft radially offset from the intermediate shafts and in communication with the output member; 
 a second countershaft radially offset from the intermediate shafts and in communication with the output member; 
 a first, second and third co-planar intermeshing gear sets, wherein the first co-planar intermeshing gear set has a first gear intermeshing with a second and third gear and the second and third co-planar intermeshing gear set has a first gear intermeshing with second gear, wherein the first gears of the second and third co-planar intermeshing gear sets are fixed for common rotation with the first intermediate shaft and the first gear of the first co-planar intermeshing gear sets is fixed for common rotation with the second intermediate shaft; and 
 a four synchronizers, wherein three of the plurality of synchronizers are selectively engagable to connect at least one of the gears of the at least three co-planar intermeshing gear sets with at least one of the first and second countershafts for common rotation therewith and wherein the fourth synchronizer is selectively engageable to connect at least one of the gears of the at least three co-planar intermeshing gear sets with at least one other of the gears of the at least three co-planar intermeshing gear sets, thereby transferring torque from the planetary gear set to at least one of the first and second countershaft transfer gears through at least one of the intermediate shafts and at least one of the sets of co-planar intermeshing gear sets. 
 
     
     
       16. The transmission of  claim 15  wherein the four synchronizers further includes a first synchronizer for selectively connecting the second gear of the first co-planar intermeshing gear sets with the second gear of the second co-planar intermeshing gear sets. 
     
     
       17. The transmission of  claim 16  wherein the four synchronizers further includes a second synchronizer for selectively connecting the third gear of the first co-planar intermeshing gear sets with the second countershaft. 
     
     
       18. The transmission of  claim 17  wherein the four synchronizers further includes a third synchronizer for selectively connecting the second gear of the second co-planar intermeshing gear sets with the first countershaft. 
     
     
       19. The transmission of  claim 18  wherein the four synchronizers further includes a fourth synchronizer for selectively connecting the second gear of the third co-planar intermeshing gear sets with the second countershaft. 
     
     
       20. The transmission of  claim 15  further comprising first and second countershaft transfer gears, wherein the first countershaft transfer gear is rotatably fixed for common rotation with the first countershaft and the second countershaft transfer gear is rotatably fixed for common rotation with the second countershaft. 
     
     
       21. The transmission of  claim 20  wherein the output member further includes an output transfer gear in mesh with each of the first and second countershaft transfer gears.